DP Chemistry (first assessment 2025)
Question 22N.2.SL.TZ0.5b
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.2.SL.TZ0.5b |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | State, Write | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 1]
22N.2.SL.TZ0.5b
(b)
Write an equation that shows how sulfur dioxide can produce acid rain.
[1]
Markscheme
SO2 (g) + H2O (l) → H2SO3 (aq)
OR
SO2 (g) + ½O2 (g) → SO3 (g) AND SO3 (g) + H2O (l) → H2SO4 (aq)
OR
SO2 (g) + ½O2 (g) + H2O (l) → H2SO4 (aq) ✔
Accept ionized forms of acids.
Examiners report
This question was poorly answered and only 30% of the candidates wrote a correct equation for the formation of acid rain from SO2. Mistakes included unbalanced equations and hydrogen added as a product.
Syllabus sections
Structure 3. Classification of matter » Structure 3.1—The periodic table: Classification of elements » Structure 3.1.5—Metallic and non-metallic properties show a continuum. This includes the trend from basic metal oxides through amphoteric to acidic non-metal oxides. Deduce equations for the reactions with water of the oxides of group 1 and group 2 metals, carbon and sulfur.